Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual foi a data da vaga para Thomas Thomasberg?
 ###Tabelas: CREATE TABLE june_draft (june_draft_id AUTO_INCREMENT PRIMARY KEY, Round INT, Name VARCHAR, Position VARCHAR, School VARCHAR, Signed VARCHAR) CREATE TABLE fifth_round_proper (fifth_round_proper_id AUTO_INCREMENT PRIMARY KEY, Tie no VARCHAR, Home team VARCHAR, Score VARCHAR, Away team VARCHAR, Date VARCHAR) CREATE TABLE episodes_and_ratings (episodes_and_ratings_id AUTO_INCREMENT PRIMARY KEY, Episode INT, First broadcast Denmark ( DR1 ) VARCHAR, Official TNS Gallup ratings INT, First broadcast UK ( BBC Four ) VARCHAR, Official BARB ratings INT) CREATE TABLE managerial_changes (managerial_changes_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Outgoing manager VARCHAR, Manner of departure VARCHAR, Date of vacancy VARCHAR, Replaced by VARCHAR, Date of appointment VARCHAR, Position in table VARCHAR) CREATE TABLE registered_births_and_deaths (registered_births_and_deaths_id AUTO_INCREMENT PRIMARY KEY, Average population (x 1000) INT, Live births VARCHAR, Deaths VARCHAR, Natural change VARCHAR, Crude birth rate (per 1000) INT, Crude death rate (per 1000) INT, Natural change (per 1000) INT)  
SELECT Date of vacancy FROM managerial_changes WHERE Outgoing manager = Thomas Thomasberg